1. Field of the Invention
The present invention relates to a desulfurization method, which can take part in environmental protection by removing detrimental hydrogen sulfide from steam exhausted from a geothermal power plant after use, and which permits the recovery of a useful byproduct from a removed sulfur component depending upon an absorbent, and a desulfurization apparatus therefor.
2. Description of the Related Art
Geothermal power generation is performed by ejecting geothermal steam through a well by taking advantage of high heat accumulated inside the earth, introducing the geothermal steam into a turbine, and driving the turbine to generate electricity. The geothermal power generation is being considered promising as an energy source following waterpower, thermal power and atomic power.
Meanwhile, geothermal steam generally contains a relatively large amount of carbon dioxide and a small amount of hydrogen sulfide. In conventional general thermal power plants, steam discharged from the turbine is cooled with a condenser to separate it into condensed water and an uncondensed gas, and the condensed water is brought back to a reducing well or recycled as a coolant, while the uncondensed gas containing the above hydrogen sulfide is released into atmosphere as it is.
The hydrogen sulfide contained in geothermal steam comes to be contained in the above uncondensed gas and released into atmosphere as it is, which causes an air pollution problem.
In recent years, therefore, constitutions having a desulfurization apparatus for removing the above hydrogen sulfide in the uncondensed gas have been proposed, as is disclosed, e.g., in Japanese Patent Provisional Publications Nos. 60-201011/'85 and 64-8363/'89.
However, conventional desulfurization apparatuses such as the above apparatuses do not take into account the disposal and recycling of a removed sulfur component in particular, and they are insufficient for practical performance in view of easiness in the disposal of a desulfurization byproduct and the redemption of an operation cost.